I. Field of the Invention
This invention relates generally to accessory tools and more particularly to an apparatus for use in assembling and disassembling a strut assembly of the type having a shock absorber axially disposed within a coil spring.
II. Description of the Prior Art
Certain types of automotive suspension systems, such as the MacPherson type, comprise a suspension sub-assembly. The sub-assembly includes a shock absorber and a spring. A part of a piston of the shock absorber projects upwardly from the strut in a telescoping fashion. A coil spring is mounted in a compressed state around the piston between a lower spring seat integral with the head end of the absorber and an upper spring seat fastened to the upper end of the piston of the shock absorber. Such a suspension sub-assembly is assembled separately and then mounted as a unit in the vehicle body. Also, during maintenance of an automobile, it is not uncommon to assemble and disassemble such suspension sub-assemblies.
During the assembly of a MacPherson-type suspension sub-assembly, the upper spring seat is disconnected from the upper end of the shock absorber piston. The coil spring is placed onto the strut with the piston extending axially through the helical spring. The lower end of the spring is disposed abutting against the lower spring seat. The coil spring is then compressed by a suitable power tool to bring the upper end of the coil spring below the upper end of the piston of the shock absorber. So compressed, the piston upper end protrudes beyond the coil spring upper end. The upper spring seat is then fastened to a threaded part of the upper end of the shock absorber piston by a nut. The spring is thus retained between the upper and lower spring seats in a compressed state. To disassemble a MacPherson-type suspension sub-assembly, the foregoing process is reversed. Namely, the coils spring is compressed by the suitable power tool and then the upper spring seat is removed. The coil is then decompressed and may be removed from the strut.
Numerous apparatus have been developed to assist in the assembly and disassembly of a strut suspension system. An example of these may be found in U.S. Pat. Nos. 4,558,500; 4,520,543; 4,516,303 and 4,494,289, to name a few. In the design of such apparatus, it is desireable to have an apparatus which can accept a wide variety of different sized MacPherson strut assemblies and to be quickly adapted by an operator to accept a particular sized strut assembly for quick and efficient assembling and disassembling. It is also recognized to be important to insure that the apparatus can securely engage and retain a spring to be compressed and otherwise insure safety to an operator since the compressed springs are compressed under a large force which, if released without control, could injure an operator.